1. Field of the Invention
The present invention relates to an electronic component tray and an identification method of a similar electronic component tray.
2. Description of the Related Art
Conventionally, an electronic component tray (hereinafter, referred to as a “tray”) has been sometimes used when electronic components such as semiconductor devices are delivered to a customer. In recent years, used trays are reused in view of environmental protection and the like.
Concretely, used trays are collected from customers, and usable trays are sorted by electronic component maker to be returned to respective electronic component makers. The electronic component maker puts electronic components in the returned trays again and delivers the electronic components to customers. The trays are sorted based on inscribed product names, maker's names, or the like, or based on the appearance such as the arrangement of resin inlet traces.
Currently, trays properly made by some makers (hereinafter, referred to as “proper trays”) are followed by a large number of trays (hereinafter, referred to as “similar trays”) that are produced by different makers but are identical or closely similar to the proper trays, not only in shape but also in inscribed product name or maker's name, the arrangement of resin inlet traces, and so on.
Constituent materials of these similar trays are unknown and possibly contain, for example, toxic substances and the like having a damaging effect on the environment. Therefore, it is not desirable to put electronic components in returned trays including similar trays to deliver them to customers. The included similar trays may possibly be a cause of loss of reliability from the customers.
Under such circumstances, it is necessary to identify similar trays that might be included in the returned trays. However, the identification of similar trays based on their appearance is difficult since even the inscribed maker's names and the like are identical or closely similar as described above.
There is disclosed an art to bury an electronic tag in a tray, the electronic tag being made of a mu-chip storing information on a tray such as its ID, maker's name and product number, and information on electronic components such as their product name, quantity, and lot number (see JP-A 2004-284601 (KOKAI)). However, burying the electronic tag in the tray is not practical since it requires a lot of trouble and increases cost.
There is disclosed another art in which a mark for identifying the type or the like of electronic components is borne on a side face of a tray (see, for example, JP-A 9-188383 (KOKAI)). However, this mark is not for enabling the identification of a similar tray but for enabling easy discrimination on the type of electronic components to be put in the tray even when the trays are in a stacked state. Further, if this mark is also imitated, it is difficult to identify a proper tray from a similar tray.